WASHINGTON (AP) - Hillary Rodham Clinton made no mention of her potential Republican rivals when kicking off her second campaign for president.
They didn't share her restraint.
Rand Paul put Clinton at the center of his first television ad, titled "Liberty, not Hillary." On Twitter, Scott Walker fired off a series of messages describing Clinton as having a "Washington-knows-best mentality." Jeb Bush derided the "Obama-Clinton foreign policy" in a video message.
Wrote South Carolina Sen. Lindsey Graham on Twitter, "The middle class is getting screwed by the administration's domestic agenda & I believe it would be more of the same with Clinton."
While there are serious policy differences among the dozen or so major Republicans considering a run for president, they appear to have all concluded there's little downside in starting early when it comes to going after Clinton - an opponent that only one of them has the chance to potentially face.
Hillary Clinton's 2016 campaign
Clinton already uniting prospective GOP presidential field
BALTIMORE, MD - APRIL 10: Democratic presidential candidate Hillary Clinton holds a campaign rally at City Garage April 10, 2016 in Baltimore, Maryland. Voters will head to polling places for Maryland's presidential primary April 26. (Photo by Chip Somodevilla/Getty Images)
Democratic U.S. presidential candidate Hillary Clinton laughs as she listens to Representative Steve Israel (D-NY) speak on a gun control panel in Port Washington, New York April 11, 2016. REUTERS/Lucas Jackson
NEW YORK, NY - APRIL 09: Democratic presidential candidate Hillary Clinton holds a Latino organizing event on April 9, 2016 while campaigning in the Brooklyn Borough of New York City. The New York Democratic primary is scheduled for April 19th. (Photo by Andrew Renneisen/Getty Images)
SPRINGFIELD, MA - FEBRUARY 29: Democratic presidential candidate former Secretary of State Hillary Clinton speaks during a 'Get Out The Vote' rally at the Lyman & Merrie Wood Museum of Springfield History on February 29, 2016 in Springfield, Massachusetts. Hillary Clinton is campaigning in Massachusetts and Virginia ahead of Super Tuesday. (Photo by Justin Sullivan/Getty Images)
BOSTON, MA - Former Secretary of State Hillary Clinton speaks to supporters at the Old South Meeting Hall during a rally in Boston, Massachusetts on Monday February 29, 2016. (Photo by Melina Mara/The Washington Post via Getty Images)
MINNEAPOLIS, MN - MARCH 01: Democratic presidential candidate former Secretary of State Hillary Clinton greets patrons at Mapps Coffee on March 1, 2016 in Minneapolis, Minnesota. Hillary Clinton is campaigning in Minnesota as Super Tuesday voting takes place in 12 states. (Photo by Justin Sullivan/Getty Images)
MOUNT VERNON, IOWA - OCTOBER 7: Former Secretary of State Hillary Clinton speaks to voters during an outdoor town hall meeting at Cornell College in Mount Vernon, Iowa on Wednesday October 7, 2015. (Photo by Melina Mara/The Washington Post via Getty Images)
MUSCATINE, IOWA - OCTOBER 6: Former Secretary of State Hillary Clinton speaks to a voter before leaving a farm in Muscatine, Iowa on Tuesday October 6, 2015. (Photo by Melina Mara/The Washington Post via Getty Images)
MANCHESTER, NH - OCTOBER 05: Democratic presidential candidate Hillary Rodham Clinton holds a town hall meeting at the Manchester Community College on October 5, 2015 in Manchester, New Hampshire. Clinton spoke about the need for gun control on the wake of a mass shooting at another community college in Oregon. (Photo by Alfredo Sosa/The Christian Science Monitor via Getty Images)
DAVIE, FL - OCTOBER 02: Democratic presidential candidate Hillary Clinton speaks about gun control during her campaign stop at the Broward College Ã Hugh Adams Central Campus on October 2, 2015 in Davie, Florida. Hillary Clinton continues to campaign for the nomination of the Democratic Party as their presidential candidate. (Photo by Joe Raedle/Getty Images)
WASHINGTON, DC - SEPTEMBER 19: Hillary Clinton attends the Phoenix Awards Dinner at the 45th Annual Legislative Black Caucus Foundation Conference at Walter E. Washington Convention Center on September 19, 2015 in Washington, DC. (Photo by Earl Gibson III/Getty Images)
MANCHESTER, NH - SEPTEMBER 19: Democratic presidential candidate Hillary Clinton claps on stage during the New Hampshire Democratic Party Convention at the Verizon Wireless Center on September 19, 2015 in Manchester, New Hampshire. Challenger for the democratic vote Sen. Bernie Sanders (I-VT) has been gaining ground on Clinton in Iowa and New Hampshire. (Photo by Scott Eisen/Getty Images)
PORTLAND, ME - SEPTEMBER 18: Hillary Clinton brings her Democratic presidential campaign to Maine for the first time, speaking at King Middle School. Clinton is welcomed as she is introduced at the event. (Photo by Derek Davis/Portland Press Herald via Getty Images)
CEDAR RAPIDS, IA - SEPTEMBER 7: Democratic Presidential hopeful Hillary Clinton takes time to meet supporters and take photos at the Annual Hawkeye Labor Council AFL-CIO Labor Day picnic on September 7, 2015 at Hawkeye Downs in Cedar Rapids, Iowa. Clinton spent a busy Labor Day weekend in Iowa, meeting supporters throughout the state while trying to maintain a lead over Bernie Sanders for the Democratic nomination. (Photo by David Greedy/Getty Images)
US Democratic presidential candidate Hillary Clinton takes part in a discussion after speaking about the Iran nuclear deal at the Brookings Institution in Washington, DC, on September 9, 2015. Clinton expressed firm support for the nuclear accord with Iran, calling it flawed but still strong. Clinton added that the agreement must be strictly enforced and said that if elected president next year, she would not hesitate to use military force if Iran fails to live up to its word and tries to develop a bomb. AFP PHOTO/NICHOLAS KAMM (Photo credit should read NICHOLAS KAMM/AFP/Getty Images)
PORTSMOUTH, NH - SEPTEMBER 5: Democratic presidential candidate Hillary Clinton and U.S. Senator Jeanne Shaheen take an off the schedule stop in the River Run Bookstore before shaking hands with onlookers on September 5, 2015 in Portsmouth, New Hampshire. (Photos by Charles Ommanney/The Washington Post via Getty Images)
PORTSMOUTH, NH - SEPTEMBER 5: Democratic Presidential candidate Hillary Clinton receives an endorsement from U.S. Senator Jeanne Shaheen (D-NH) September 5, 2015 in Portsmouth, New Hampshire. Clinton attended a Women for Hillary event at Portsmouth High School. (Photo by Darren McCollester/Getty Images)
PORTSMOUTH, NH - SEPTEMBER 5: Democratic Presidential candidate Hillary Clinton walks downtown Portsmouth and takes pictures with people September 5, 2015 in Portsmouth, New Hampshire. Clinton attended a Women for Hillary event at Portsmouth High School earlier in the day and received an endorsement from U.S. Senator Jeanne Shaheen (D-NH). (Photo by Darren McCollester/Getty Images)
LAS VEGAS, NEVADA - AUGUST 18: Former Secretary of State Hillary Clinton answers questions from journalists after speaking to north Las Vegas voters at a town hall meeting in Las Vegas, on Tuesday, August 18, 2015. The former Secretary was answering questions about emails sent and received a private server system, now in question, while she was the Secretary of State. (Photo by Melina Mara/The Washington Post via Getty Images)
UNITED STATES - August 15: Democratic presidential candidate Hillary Rodham Clinton greets fairgoers as she tours the Iowa State Fair in Des Moines, Iowa, on Saturday, August 15, 2015. (Photo By Al Drago/CQ Roll Call)
CARROLL, IA - JULY 26: Democratic presidential hopeful and former Secretary of State Hillary Clinton speaks to guests gathered for a house party on July 26, 2015 in Carroll, Iowa. Although Clinton leads all other Democratic contenders, a recent poll had her trailing several of the Republican candidates in Iowa. (Photo by Scott Olson/Getty Images)
CHICAGO, IL - MAY 20: Democratic presidential hopeful and former Secretary of State Hillary Clinton arrives for a meeting with parents and child care workers at the Center for New Horizons on May 20, 2015 in Chicago, Illinois. Clinton arrived in Chicago after campaigning Monday and Tuesday in Iowa. (Photo by Scott Olson/Getty Images)
LAS VEGAS, NV - MAY 05: Democratic presidential candidate and former U.S. Secretary of State Hillary Clinton (C) poses with students and faculty after speaking at Rancho High School on May 5, 2015 in Las Vegas, Nevada. Clinton said that any immigration reform would need to include a path to 'full and equal citizenship.' (Photo by Ethan Miller/Getty Images)
NEW YORK, NY - APRIL 23: Hillary Rodham Clinton (L) and actress Maggie Gyllenhaal attend the 2015 DVF Awards at United Nations on April 23, 2015 in New York City. (Photo by Michael Stewart/FilmMagic)
NEW YORK, NY - APRIL 29: Democratic presidential hopeful and former Secretary of State Hillary Clinton speaks during the David N. Dinkins Leadership and Public Policy Forum at Columbia University April 29, 2015 in New York City. Clinton addressed the unrest in Baltimore, called for police body cameras and a reform to sentencing. (Photo by Kevin Hagen/Getty Images)
Hillary Clinton announced her campaign for president on Sunday April, 12, 2015 with a video on YouTube.
(Screenshot from YouTube)
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Even former Massachusetts Gov. Mitt Romney, the party's 2012 nominee, couldn't resist taking a shot at Clinton on Sunday.
"Hillary Clinton is just not trustworthy," he said on "Fox News Sunday." ''She's a creature of Washington."
Meantime, she hit the road - quite literally.
Clinton left Sunday on a road trip from her home in Chappaqua, New York, in a van headed for Iowa, home of the nation's first presidential caucuses.
The former secretary of state will hold her first campaign event on Tuesday in eastern Iowa. The road trip was Clinton's idea, aides said.
Longtime aide Huma Abedin, in a conference call with Clinton alumni, said that Clinton's van stopped at a gas station in Pennsylvania, where the former first lady and New York senator met a family from Michigan.
Hillary Clinton through the years
Clinton already uniting prospective GOP presidential field
A 1992 photo shows then Governor of Arkansas Bill Clinton (L) and his wife Hillary (R) embracing. (Photo credit AFP/Getty Images)
Democratic presidential candidate Bill Clinton (L) waves to supporters as he holds the hand of his wife Hillary, 22 July, 1992 after speaking at a rally. St. Louis was the last stop on the Clinton-Gore campaign's bus tour. The crowd was estimated at 40,000. (Photo credit Tim Clary, AFP/Getty Images)
US President Bill Clinton's wife Hillary Rodham Clinton (l) in a picture taken 16 January 1993 in Little Rock, hugs her daughter Chelsea during a farewell address to the people of Arkansas at an airport rally. The Clinton family then left for Charlottesville, Virginia for the start of the planned bus trip to Washington, DC. (Photo credit J. David Ake, AFP/Getty Images)
First Lady Hillary Clinton (R) watches over as 12-year-old Chevon Perry (L) works on a lesson at P.S. 115 Elementary School 26 January 1993. Clinton made her first trip as first lady to New York to receive an award for her service to children. (Photo credit Tim Clary, AFP/Getty Images)
First Lady Hillary Clinton responds to applause, 12 February 1993, in Arlington, VA, as U.S. President Bill Clinton stands behind her. (Photo credit Robert Giroux, AFP/Getty Images)
U.S. First Lady Hillary Rodham Clinton laughs as she is presented a bouquet of flowers by Japanee children 08 July 1993 at the Meguro waste incineration plant in Tokyo, Japan. Mrs. Clinton, maintaining a high profile during the G7 summit, is popular in Japan. (Photo credit David Nelson, AFP/Getty Images)
U.S. President Bill Clinton (R) and First Lady Hillary Rodham Clinton (L) listen to Karl Kregor explain, 16 September 1993 in Washington, D.C. why he is afraid of losng health isurance for his family.The Clintons met at the White House with citizens who shared problems they have had with the present health care system. Clinton is scheduled to present his health care plan to a joint session of congress 22 September. (Photo credit Paul Richards, AFP/Getty Images)
U.S. First Lady Hillary Clinton responds 22 September 1993 to applause from a joint session of the U.S. Congress in Washington, D.C. after President Bill Clinton saluted her as the 'talented navigator' for the national health plan he is proposing. Standing alongside the first lady is Dr. T. Berry Brazelton (L), a noted pediatrician and author. (Photo credit J. David Ake, AFP/Getty Images)
First Lady Hillary Clinton attends the Winter Olympics in Lillehammer, Norway. (Photo by Clive Brunskill, Getty Images)
US First Lady Hillary Clinton (L) and Wife of French Prime Minister Edouard Balladur, Marie-Josephe Balladur pose at the Hotel Matignon on June 7, 1994. (Photo credit Pascal Pavani, AFP/Getty Images)
First Lady Hillary Rodham Clinton (C) smiles at a friend in the crowd 28 September 1994 as she stands next to Russian First Lady Naina Yeltsin (L) during a ceremony at the Library of Congress. Mrs. Yeltsin was accompanying her husband on his visit to Washington for a summit meeting with US President Bill Clinton. AFP YEARENDER (Photo credit Joshua Roberts, AFP/Getty Images)
US President Bill Clinton (R) and First Lady Hillary Clinton leave the White House for the presidential retreat at Camp David, Maryland, 13 Janaury. President Clinton is waving a copy of the morning pool report on his activities, which was written as a poem. The poem begins ' The president jogged at Fort McNair....of him we saw not hide nor hair,' and ends with the slogan 'Burma Shave.' (Photo credit Paul Richards, AFP/Getty Images)
US First Lady Hillary Clinton laughs as she listens to political humorist Bill Maher address the annual dinner of the Radio and Television Correspondents Association in Washington on March 14, 1995. (Photo credit Paul J. Richards, AFP/Getty Images)
US First Lady Hillary Clinton (L) poses with 'Robo Crook'(R) a character from the television program Sesame Street at the White House in Washington, DC 26 June. Mrs. Clinton moderated a panel discussion on the role of Public Television in educating children. (Photo credit Jamal Wilson, AFP/Getty Images)
Hillary Clinton, wife of US President Bill Clinton, talks with Britain's Queen Elizabeth 30 November in the Grand Entrance Hall of Buckingham Palace in London. President Clinton and Hillary Clinton arrived 29 November morning for a three-day visit which will be dominated by the Northern Ireland peace process. (Photo credit John Stillwell, AFP/Getty Images)
US First Lady Hillary Clinton greets guests after speaking at the Women's Leadership Forum at the World Trade Center 20 June in Boston, Massachusetts.The First Lady will be in Washington DC later 20 June for the arrival of the Olympic Torch at the White House. (Photo credit John Mottern, AFP/Getty Images)
US First Lady Hillary Rodham Clinton waves from the bullet-proof presidential limousine as she and US President Bill Clinton leave Sydney International Airport on November 19, 1996. The Clintons arrived in Australia from Hawaii at the start of a five-day working and holiday visit. A(Photo credit should read Torsten Blackwood, AFP/Getty Images)
US President Bill Clinton (L)and his wife Hillary listen to speakers at a coalition for America's Children event at the White House in Washington, on March 3, 1997. The Clintons will begin a series of television, radio and newspaper public service annoucements, urging Americans to help improve the lives of children. (Photo credit Joyce Naltchayan, AFP/Getty Images)
Hillary Clinton proudly shows the tea-pot which had been a gift from community worker Joyce McCartan on the Clintons' previous visit to Belfast, during her speech at the University of Ulster, in Belfast 31 October. The memorial speech, named after Joyce McCartan, who died last year, called on parties from both sides to make compromises for peace in the country. The American First Lady is on a whistle-stop tour visiting Dublin, Belfast and London in three days. (Photo credit Alan Lewis, AFP/Getty Images)
US First Lady Hillary Clinton talks with NBC TV anchorwoman Katie Couric (L)10 September during an event in the East Room of the White House promoting colon cancer awareness and prevention. Hillary Clinton announced a new research grant to fight colon cancer and unveiled a new public service announcement to promote prevention. (Photo credit Tim Sloan, AFP/Getty Images)
US President Bill Clinton, First Lady Hillary Clinton, and their daughter Chelsea tour the Forbidden City in Beijing, as a Chinese security agent (rear) looks on 28 June during their 9 day official trip to China. The three later toured the Great Wall. (Photo credit Paul J. Richards, AFP/Getty Images)
US First Lady Hillary Rodham Clinton listens to speakers during ceremonies 11 January to unveil the new Dolley Madison commemorative silver dollar coin at the White House in Washington, DC. The coin, designed by Tiffany and Company is available at the US Mint and celebrates the life, achievements and 150th anniversary of Dolley Madison's death. (Photo credit Tim Sloan, AFP/Getty Images)
First Lady Hillary Clinton works the crowd as she arrives at Prior Aviation Services in Buffalo, New York, 07 February, 2000. Mrs. Clinton, who officially announced her run for US Senate 06 February, 2000, made Buffalo her fisrt campaign stop. ((Photo credit Don Emmert, AFP/Getty Images)
US First Lady Hillary Rodham Clinton (R) announces the formation of the Millenium Trails Celebration Committee 19 April, 1999 at the Central Park Boathouse in New York, New York. Millenium Trails is a national initiative to create and enhance hiking, cultural and other trails across the country. It partners the White House Millenium Council, the Department of Transportation and the Rails-to-Trails Conservancy. (Photo credit Stan Honda, AFP/Getty Images)
US President Bill Clinton (L) and First Lady Hillary Rodham Clinton (R) wait on the South Portico for the arrival of King Juan Carlos I and Queen Sofia 23 February 2000 at the White House in Washington, DC. The Clintons hosted an arrival ceremony for their visit. (Photo credit Stephen Jaffe, AFP/Getty Images)
US First Lady and New York US Senate candidate Hillary Clinton waves to the crowd as she arrives on the stage at the Democratic National Convention 14 August 2000 at the Staples Center in Los Angeles, California. (Photo credit Paul J. Richards, AFP/Getty Images)
U.S. Senate candidate and First Lady Hillary Rodham Clinton gives a thumbs-up sign to supporters at the Hispanic Day Parade October 8, 2000 in New York City. (Photo by Chris Hondros/Newsmakers via Getty)
US First Lady Hillary Clinton smiles during a press conference in New York 08 November, 2000. Clinton defeated Congressman Rick Lazio to win the US Senate seat for New York being vacated by Patrick Moynihan. AFP PHOTO Doug KANTER (Photo credit Doug Kanter, AFP/Getty Images)
U.S. Senator-elect, First Lady Hillary Clinton walks through the U.S. Capitol during an orientation day for new senators December 5, 2000 in Washington, DC. (Photo by Mark Wilson/Newsmakers via Getty)
Senator Hillary Rodham Clinton listens during Labor Secretary-designate Elaine Chao's confirmation hearing January 24, 2001 on Capitol Hill in Washington, DC. (Photo by Alex Wong/Newsmakers via Getty)
Sen. Hillary Rodham Clinton (D-NY) attends a press conference to address the equal pay act June 12, 2001 Capitol Hill in Washington, DC. The AFL-CIO''s Working Women Working Together held a news conference to introduce a campaign for legislation to step up enforcement of the 1963 Equal Pay Act. (Photo by Alex Wong/Getty Images)
New York Senator and former First Lady, Hillary Rodham Clinton, signs copies of her autobiography, 'Living History' at Waterstone?s bookstore on July 3, 2003 in London, England. In her autobiography, Clinton reveals her presidential ambitions and her thoughts on Monica Lewinsky. (Photo by Scott Barbour/Getty Images)
Senator Hillary Rodham Clinton appears with Jon Stewart during 'The Daily Show With Jon Stewart' at the Daily Show Studios October 8, 2003 in New York City. (Photo by Scott Gries/Getty Images for The Daily Show)
Sen. Hillary Rodham Clinton (D-NY) attends a news conference in front of the United Nations to denounce the International Court of Justice's recent decision on Israel's security fence July 9, 2004 in New York City. The International Court in The Hague has ruled that the barrier Israel has nearly completed in the West Bank violates international law, and the court ruled that the United Nations should take action to stop its construction. (Photo by Spencer Platt/Getty Images)
U.S. Senator Hillary Rodham Clinton (D-NY) speaks while former U.S. President Bill Clinton listens during a visit to the New York Buddhist Vihara December 31, 2004 in the Queens borough of New York City. The Clintons toured the temple where volunteers have been collecting donations for victims of the tsunami in Sri Lanka. (Photo by Stephen Chernin/Getty Images)
Sen. Hillary Rodham Clinton (D-NY) speaks at a Democratic forum on Social Security reform at Pace University March 4, 2005 in New York City. A group of Democratic Senators spoke at the forum to protest U.S. President George W. Bush's plan to privatize Social Security. (Photo by Mario Tama/Getty Images)
U.S. Senator Hillary Clinton (D-NY) stands near her portrait during an unveiling ceremony at the Smithsonian April 24, 2006 in Washington DC. President Clinton's portrait will hang in the National Portrait Gallery's 'America's President's' exhibit. (Photo by Mark Wilson/Getty Images)
Hillary Rodham Clinton watches a speaker on the final day of the Clinton Global Initiative annual meeting September 22, 2006 in New York City. A large array of notables in the worlds of politics, human rights, and philanthropy have gathered in the New York for three days of seminars and pledges on global issues. (Photo by Chris Hondros/Getty Images)
Democratic presidential hopeful Sen. Hillary Clinton (D-NY) speaks during a post primary rally at Southern New Hampshire University January 8, 2007 in Manchester, New Hampshire. After losing to Sen. Barack Obama (D-IL) and Edwards in Iowa, Clinton (D-NY) won New Hampshire, the first of the nation's presidential primaries. (Photo by Chris Hondros/Getty Images)
US Senator Hillary Clinton and daughter Chelsea are seen at the lectern during a soundcheck at the Democratic National Convention 2008 at the Pepsi Center in Denver, Colorado, on August 26, 2008. Clinton takes the stage tonight vowing to unite Democrats after her primary battle with Barack Obama, on the second day of the convention that will crown him as White House nominee. The DNC is held 25-28 August. (Photo credit Stan Honda, AFP/Getty Images)
Democratic presidential nominee U.S. Sen. Barack Obama (D-IL) and Sen. Hillary Clinton (D-NY) attend a campaign rally together at Amway Arena October 20, 2008 in Orlando, Florida. Obama continues to campaign against his challenger, Republican presidential nominee Sen. John McCain (R-AZ) while Election Day begins to draw near. (Photo by Joe Raedle/Getty Images)
Former US President Bill Clinton (L) and US Secretary of State-designate Hillary Clinton (R) attend the inauguration of US President Barack Obama at the US Capitol in Washington, DC, on January 20, 2009. (Photo credit Robyn Beck, AFP/Getty Images)
U.S. Secretary of State Hillary Clinton (L) is sworn in as her husband former President Bill Clinton (2nd L), and her daughter Chelsea (R) look on during a ceremonial swearing-in at the State Department February 2, 2009 in Washington, DC. Clinton is the 67th Secretary of State of the United States of America. (Photo by Alex Wong/Getty Images)
US Secretary of State Hillary Clinton attends a press conference on February 21, 2009 in Beijing, China. Clinton is on a three day visit to the Chinese capital, as part of her first diplomatic tour to Asia. (Photo by Guang Niu/Pool/Getty Images)
US Secretary of State Hillary Clinton speaks on the US vision for Asia-Pacific multilateral engagement at the East-West Center in Honolulu January 12, 2010. (Photo credit Mandel Ngan, AFP/Getty Images)
US Secretary of State Hillary Clinton, smiles during a press conference after Middle East Quartet talks in Moscow on March 19, 2010. The International Quartet on the Middle East urged Israel to freeze all settlement activity and expressed deep concern about the situation in Gaza, UN Secretary General Ban Ki-moon said. (Photo credit Yuri Kadobnov, AFP/Getty Images)
US Secretary of State Hillary Clinton speaks before signing the US-China Consultation on People-to-People Exchange agreement at the National Center for the Performing Arts in Beijing on May 25, 2010. The United States and China were wrapping up strategic talks aimed at smoothing out differences on currency and trade issues, as Washington presses Beijing to get tough on North Korea. (Photo credit Saul Loeb, AFP/Getty Images)
U.S. Secretary of State Hillary Clinton listens to Ambassador-Designate to Russia Michael McFaul during his swearing-in ceremony at the State Department January 10, 2011 in Washington, DC. McFaul is President Barack Obama's top adviser on Russia and has been involved in the reset of relations between the two countries and the signing of the New START treaty. (Photo by Astrid Riecken/Getty Images)
U.S. Secretary of State Hillary Clinton speaks during the South Sudan International Engagement Conference December 14, 2011 at the Marriott Wardman Park Hotel in Washington, DC. The two-day conference was to highlight the national development vision of South Sudan and the opportunities for investment in the country. (Photo by Alex Wong/Getty Images)
US Secretary Hillary Clinton speaks to reporters during a joint press conference with Qatar's Prime Minister and Foreign Minister Hamad bin Jassim bin Jabr Al-Thani at the Department of State January 11, 2012 in Washington, DC. (Photo credit Karen Bleier, AFP/Getty Images)
US Secretary of State Hillary Clinton (R) shakes hands with Moroccan Foreign Minister Saad-Eddine el-Othmani prior to meetings at the State Department in Washington, DC, on March 15, 2012. (Photo credit Saul Loeb, AFP/Getty Images)
US Secretary of State Hillary Clinton smiles during a joint press conference with Australian Foreign Minister arr following their meeting at the State Department in Washington, DC, on April 24, 2012. (Photo credit Jewel Samad, AFP/Getty Images)
U.S. Secretary of State Hillary Clinton testifies before the House Foreign Affairs Committee on Capitol Hill January 23, 2013 in Washington, DC. Lawmakers questioned Clinton about the security failures during the September 11 attacks against the U.S. mission in Benghazi, Libya, that led to the death of four Americans, including U.S. Ambassador Christopher Stevens. (Photo by Chip Somodevilla/Getty Images)
Former US Secretary of State Hillary Clinton addresses the Vital Voices Global Awards ceremony at the Kennedy Center in Washington on April 2, 2013. The event honors 'women leaders from around the world who are the unsung heroines to strengthen democracy, increase economic opportunity, and protect human rights,' according to the group's website. (Photo credit Nicholas Kamm, AFP/Getty Images)
Former US Secretary of State Hillary Clinton speaks about the situation in Syria after meeting with US President Barack Obama, prior to remarks about US efforts to combat wildlife trafficking at a White House forum at the Eisenhower Executive Office Building in Washington, DC on September 9, 2013. (Photo credit Saul Loeb, AFP/Getty Images)
Former Secretary of State Hillary Rodham Clinton speaks on stage at the Pennsylvania Conference For Women 2013 at Philadelphia Convention Center on November 1, 2013 in Philadelphia, Pennsylvania. (Photo by Lisa Lake/Getty Images for Pennsylvania Conference for Women)
Hillary Clinton attends the New-York Historical Society 2014 History Makers Gala at Mandarin Oriental Hotel on November 21, 2014 in New York City. (Photo by Brad Barket/Getty Images)
Hillary Rodham Clinton Book Signing For 'Hard Choices' at Barnes & Noble bookstore at The Grove on June 19, 2014 in Los Angeles, California. (Photo by Frazer Harrison/Getty Images)
Former U.S. Secretary of State Hillary Clinton delivers a keynote address during the Watermark Silicon Valley Conference for Women on February 24, 2015 in Santa Clara, California. Former Secretary of State Hillary Clinton delivered a keynote address to thousands of women in attendance for the Watermark Silicon Valley Conference for Women. (Photo by Justin Sullivan/Getty Images)
Former Secretary of State Hillary Clinton speaks on stage during a ceremony to induct her into the Irish America Hall of Fame on March 16, 2015 in New York City. The Irish America Hall of Fame was founded in 2010 and recognizes exceptional figures in the Irish American community. (Photo by Yana Paskova/Getty Images)
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A Clinton aide said the van is nicknamed "Scooby" after the Mystery Machine van in the 1970s animated television show, "The Scooby Doo Show." The aide said Clinton was a passenger and the van was driven by the Secret Service. The trip will cover roughly 1,000 miles between Clinton's home in New York City's suburbs and Iowa. Clinton expects to arrive in the state on Monday and is appearing at a community college in Monticello, Iowa, on Tuesday.
In the hours before she formally entered the race in a video posted to her website on Sunday, Clinton was subject to withering criticism from Republicans such as Romney who showed up on the Sunday morning political talk shows. In the hours that followed, there was more of the same - with the added request for donations.
Bush hit up supporters with a fundraising appeal to help him stop Clinton's "liberal agenda." Paul started selling "Hillary's Hard Drive" on his website, a not-so-subtle reference to Clinton's use of a personal email account and server while serving as secretary of state.
The salvos at Clinton come amid an already-underway effort by the Republican National Committee and a series of conservative groups to paint Clinton in a negative light. At least 10 political organizations list defeating Clinton as their primary mission in their filings with the Federal Election Commission, and Democrats say they're preparing to face much as $500 million worth of attack ads during the 2016 election.
While the early efforts aim to highlight Clinton's potential vulnerabilities, Republicans also see these initial emails, videos and tweets as an opportunity to collect valuable email addresses and other data about potential supporters.
2016 Democratic candidates Clinton, etc
Clinton already uniting prospective GOP presidential field
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"Ninety-eight percent of our focus has been on Hillary for the last year," said Sean Spicer, the chief strategist and communications director of the Republican National Committee. "And having all this digital political and communication assets focused on Hillary gives us a massive advantage. It's one thing to motivate your base, it's another thing to activate them."
Republican strategists say the Clinton-focused messages appeal to primary voters by demonstrating a candidate's ability to take her on in the general election.
Florida Sen. Marco Rubio's team was initially concerned that coverage of Clinton's announcement would crowd out coverage of their splashy Monday night rally that's expected to kick off his 2016 campaign. They later concluded the almost overlapping events would draw a powerful contrast between Rubio, the 43-year-old senator, and Clinton, who is almost 25 years his senior.
It's a calculus that didn't occur, or didn't matter, to Clinton. Her video, shared hundreds of thousands of times in the first hour after being posted online, said nothing about anyone else in the 2016 race.
An old Clinton rival from Arkansas who is also considering a run for president, former Gov. Mike Huckabee, predicted that silence won't last.
"Anyone who thinks that she's going to get into this halfheartedly, well, they've never ever encountered the will, the spirit, the heart and the determination of the Clinton political machinery," he said on ABC's "This Week."
Associated Press writer Philip Elliott contributed to this report from Washington.